package thread;

public class SyncDemo4 {
    public static void main(String[] args) {
        Boo boo = new Boo();
        Thread t1 = new Thread(() -> boo.methodA());
        Thread t2 = new Thread(() -> boo.methodB());
        t1.start();
        t2.start();
    }
}

class Boo {
    public synchronized void methodA() {
        try {
            Thread t = Thread.currentThread();
            System.out.println("正在执行A方法...");
            Thread.sleep(5000);
            System.out.println("A方法执行完毕");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public /*synchronized*/ void methodB() {
        synchronized ("this") {
            try {
                Thread t = Thread.currentThread();
                System.out.println("正在执行B方法...");
                Thread.sleep(5000);
                System.out.println("B方法执行完毕");
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}